Bees are making a comeback in parts of Europe, according to a study in Ecology Letters.

Much of the news about biodiversity these days is gloomy. But over the last couple of decades, some countries have adopted environmentally-friendly policies to bring species back. Now the question is: Did those programs work?

To find out, a team combed more than 29 million records of bees, butterflies, hoverflies, and plants dating back to 1930 in the UK, Belgium, and the Netherlands. From the 1950-60s to the 1970-80s, species richness did drop for the three groups of insects. Dutch and Belgian bees fared especially poorly, and every country saw butterfly declines.

When the researchers compared the 1970-80s to the 1990-2000s, though, they found some optimistic signs. Species were still being lost, but at a slower rate. And for some insects, the trend was reversed: The number of bee species (not including bumblebees) in the UK and the Netherlands and hoverfly species in Belgium increased.

Species “will likely continue to bear the marks of past declines for a long time; yet they remain diverse,” the authors write. At least in some areas, they say, “conservation efforts may be paying off.” — Roberta Kwok | 27 May 2013